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48000 vs 48048
I’m working on a film shot at 24 with telecine to HD. My FCP5 project is at 23.98. The sound recordist is recording with a Deva sampling at 48048 but time stamping at 48000. When I bring the sound into FCP it’ll pull down from 48048 to 48000 which is exactly the pulldown difference of 0.1% that the picture goes through when it pullsdown from 24 to 23.98.
Except it doesn’t.
I can run the sound through BWF2XML set at 24 and that makes the pulldown happen but as far as I know, FCP should be fooled into thinking that the sounds recorded at 48000 because of the time stamp thus playing it back slower. A friend of mine has done it but he was on 4.5 and I’m on 5 but I don’ know if that makes a difference. I know that he could subclip and that I can’t but that’s another matter entirely.
What am I doing wrong? If anyone has an idea, I’d appreciate it greatly.
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5 Replies
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Is the sound early or later than picture?
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Also, double check in final cut pro that the sample rate is truly stamped at 48 and not 48048. If he recorded at 48048 and it’s stamped as such…final cut WILL NOT do this conversion for you. The trick will not work.
And you are working in a 23.98 timeline and not 24 correct?
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Mike,
I am working in a 23.98 timeline, my sequence presets is DVCPro HD – 720p24. It says to use this preset when editing with 720p DVCPro HD 23.98fps.
The sound comes up early. If I slow it down in FCP to 99.9% it’s in perfect sync which means that the pulldown isn’t happening. In the Browser the sound shows 48.0KHz and the sound recordist is adamant that he’s recording 48048 stamping at 48 and giving me Poly F files. Is there an application I can use to open up the sound that’ll show me the true metadata because the Browser doesn’t actually show that stuff. I could do it in Pro Tools I guess…?
Any more thoughts?
Thanks for your interest.
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Here…if you apply the sound clip to the timeline and it has a green real time render bar above, final cut is applying a conversion on the fly to the 48048 (if that’s the data rate) making it 48….BUT this still means you have to change to 99.9 percent.
This means that your sound guy recorded and stamped at 48048. You could open audio files in another audio program and attempt to alter the audio stamp but not convert the sample rate.
If you’re applying it to the timeline and there’s no green bar and it’s not playing back slower, than he recorded and stamped it at 48 and stamped it 48.
Eiter way in these cases…you’re going to have to do the speed change of 99.9 % to maintain sync.
There was a mistake done in your process at some point.
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I’ve got it figured!
There was nothing wrong with my workflow (I knew it!!).
The sound was recorded on a Deva 5 using version 2.07.
The Deva can record 48048 but stamp at 48000 if using the F (for Fostex) facility. If FCP reads the stamp at 48000 it will automatically pull the sound down by 0.1% to match the picture that is running at 23.98. It is really important that this happens otherwise we will be really stuck when we get to the mix when we master back to 24fps.So here’s what happened… Deva released a new version of their software – 2.10. That fixed it. The problem was with the Deva. No wonder older versions worked fine, it was just 2.07 that was bugged. FCP works like a charm now so no need to use the dodgy way that BWF2XML makes referencing pulled down files anymore.
Unfortunately, the Deva guys at Zaxcom don’t seem to be very aware of this problem and it seems to have been fixed by accident in the new version. They just seem to be going on about the Timecode Stamp Pullup and Pulldown buttons that don’t affect what I’m talking about at all.
If anybody else seems to be having this trouble, make sure that the Deva OS is 2.10!
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